Beat butter, sugar and vanilla in small bowl with electric mixer until smooth.,Transfer to a large bowl, stir in flour in two batches.,Dissolve coffee in water, stir coffee mixture into dough.,Spoon mixture into piping bag fitted with a 2cm fluted tube.,______,Sprinkle with 1 tbs demera or white sugar if desired.,Bake 160C for about 15 minutes.,Cool on tray.,Thermomix instructions.,Mill sugar, 10 sec, speed 9.,Add butter and vanilla and mix 1 minute, speed 4.,Scrape jug and mix 20 seconds, speed 4.,Add flour and mix 20 seconds, speed 2.,Scrape and mix for another 10 seconds, speed 2.,Add coffee mixture and mix 20 seconds, speed 2.,Check to see if coffee is properly mixed.,Mix another 10 seconds if necessary.,I found refrigerating for 1/2 hour before baking improved the look of the biscuits.